Tonight Jason Scott ran a twitch.tv cast of himself looking through "Internet Archive on a CD-ROM" and I saw a number of square images that were intended to be used as background images for either web pages or desktops. Many of the images looked like they were designed to be tiled and the edges were intended to line up when tiled so the overall background would appear "seamless". I believe some of them were generated using this RepTile application made by Sausage Software which had the web site http://www.sausage.com/ - here is a Wayback snapshot I found with a description of the application (version 2).